1. Field of the Invention
The present invention relates to an optical access system and apparatus and method, and more particularly, to a technique for connecting an optical access network to a user network.
2. Description of Related Art
First, a conventional optical network termination apparatus (ONT) inserted between an optical access network and a user terminal for termination of optical line, will be described with reference to FIG. 4. FIG. 4 is a block diagram showing an optical access system including the conventional optical network termination apparatus.
As shown in FIG. 4, a conventional optical network termination apparatus 1 is connected to an optical access network 200. When a user terminal 50 performs communication with another user terminal connected to the optical access network 200 or another node, the apparatus realizes information transmission/reception by termination of optical line.
For example, the ITU-T recommends xe2x80x9cHigh Speed Optical Access Systems Based on Passive Optical Network (PON) Techniquesxe2x80x9d of functions of ATM optical network termination apparatus.
In the conventional optical access system, the optical network termination apparatus 1 is connected to the optical access network 200, but is not connected to a user network 100. In this construction, the user terminal 50 accesses a node A or B in the user network 100 independently of the optical network termination apparatus 1.
That is, as the optical access network 200 and the user network 100 are isolated from each other, it is impossible to, e.g., provide a node to monitor-control the optical network termination apparatus, in the node A or B in the user network 100.
Further, it is also impossible to transfer information from the optical access network 200 to the user network 100 and transfer a response to the information from the user network 100 to the optical access network 200.
As described above, in the conventional optical-network termination apparatus 1, it is impossible to connect the optical access network 200 to the user network 100, and it is difficult to transmit/receive information between these two networks.
Further, as the optical network termination apparatus 1 is usually provided in a user""s house, if a part of functions of the user terminal 50 connected to the user network 100 can be performed by the optical network termination apparatus 1, the efficiency of use of the optical network termination apparatus 1 can be improved. However, as the conventional optical network termination apparatus 1 is not connected to the user network 100, the optical network termination apparatus cannot perform the part of functions of the user terminal 50.
The present invention has been made in consideration of the above situation, and has its object to provide an optical network termination apparatus which connects a user network to an optical access network. Further, another object of the present invention is to provide an optical network termination apparatus for monitor control from a user network. Further, another object of the present invention is to provide an optical network termination apparatus which performs a part of functions of a user terminal such as a personal computer connected to a user network.
According to the present invention, an optical network termination apparatus has a function for connection with a user network, thereby connects an optical access network to the user network. By this arrangement, overlapping services in the optical access network and the user network can be provided. Further, a part of functions of the optical network termination apparatus can be utilized as a part of functions of the user terminal.
The present invention provides an optical network termination apparatus, which is provided between an optical access network and a user terminal and which has means for terminating an optical line, comprising: connection means for connection with a user network to which the user terminal is connected; wherein the connection means includes means for inputting, in accordance with a set address, information having the address from the user network, and means for transmitting the information having the address to the user network.
It is preferable that the optical network termination apparatus further comprising address setting means for setting the address, and the address setting means includes means for setting an address in the connection means in accordance with address information written in an external storage medium.
In the optical network termination apparatus, a CPU to control the connection means may be provided in addition to a CPU to control the overall optical network termination apparatus. Further, in the optical network termination apparatus, a memory for the CPU to control the connection means may be provided in addition to a memory for the CPU to control the overall optical network termination apparatus.
Further, more particularly, the present invention provides an optical network termination apparatus having: a transmission/reception circuit connected to a user terminal and an optical access network; a first reception buffer connected to output of the transmission/reception circuit; a CPU communication format converter which inputs output from the first reception buffer and converts a format of the output and outputs the output to the CPU bus; a RAM, a ROM, a CPU and a main signal communication format converter, connected to the CPU bus; a transmission buffer in which output from the main signal communication format converter is inputted; a main signal insertion circuit which inputs output from the transmission buffer and/or a main signal from the optical access network and a main signal from inside the apparatus itself, and outputs them to the transmission/reception circuit; and a second reception buffer in which output from the main signal insertion circuit is inputted and from which the output is outputted to the CPU communication format converter.
In this construction, the transmission/reception circuit includes connection means for connection with a user network, and wherein the connection means includes: means for inputting, in accordance with a set address set in the CPU communication format converter and the main signal communication format converter, information having the address from the user network, and means for transmitting the information having the address to the user network.
It is preferable that in the optical network termination apparatus, an external storage medium R/W device in which the address is set is provided, and wherein the external storage medium R/W device includes means for setting an address in the CPU communication format converter and the main signal communication format converter in accordance with address information written in an external storage medium.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same name or similar parts throughout the Figures thereof.